


I'm Yours

by flowerwoo



Series: Grey Diamond [3]
Category: ATEEZ (Band)
Genre: Alpha Park Seonghwa, Alpha/Beta/Omega Dynamics, Fluff, Fluff and Smut, I cant write smut for the life of me, I couldnt help myself, M/M, Omega Kim Hongjoong, Smut, Teasing, Two Chapters, seonghwa is an alpha in chapter 1 but an omega in chapter 2, soft
Language: English
Status: Completed
Published: 2020-10-16
Updated: 2020-10-16
Packaged: 2021-03-09 06:02:29
Rating: Mature
Warnings: Underage
Chapters: 2
Words: 3,948
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27039910
Author URL: https://archiveofourown.org/users/flowerwoo/pseuds/flowerwoo
Summary: Chapter 1-Hongjoong omega x Seonghwa alphaChapter 2- Seonghwa omega x Hongjoong alphaWhen the taste of the “food” hit him, he opened his eyes sharply, eyebrows furrowed. He quickly realised Seonghwa was naked in the sheets, laying on his stomach with his chin in his hands, with no sight of food beside him. Seonghwa had fed him his own cum.
Relationships: Kim Hongjoong/Park Seonghwa
Series: Grey Diamond [3]
Series URL: https://archiveofourown.org/series/1943770
Kudos: 63





	1. Hongjoong omega x Seonghwa alpha

**Author's Note:**

> I think this could be read as a solo fic but if it helps you can check out part 1 and part 2 of this series! It might be easier. Idk. TOODLES

Hongjoong being off suppressants meant that his pheromones could be smelled more clearly. Seonghwa had decided to stay at home to help him through his heat, and Hongjoong was more than happy to spend some quality time with his husband. His pre-heat went smoothly, as Seonghwa thinks. Hongjoong became more clingy and  _ way  _ more affectionate than usual. During most days, he would hate whenever Seonghwa gave him a kiss. Now, he was asking Seonghwa for kisses nearly every second. Seonghwa found this hard to get used to, but complied, being more than willing to give Hongjoong his kisses. He simply wouldn’t have it any other way. 

On the first day of Hongjoong’s heat, Seonghwa woke up to a heavy, intoxicating strawberry scent. He turned over to see Hongjoong laying in a pool of his own slick, fingers in his ass. It didn’t take long for Seonghwa to figure out what he had to do next, his instincts were propelling him forward. 

“Aww baby~” Seonghwa cooed. He took this opportunity, rushing over to put his face in between his legs, excited to help Hongjoong through his heat. 

“Hwa~” Hongjoong glanced up at him, spreading his legs to give his alpha a better view of the wet mess. 

Seonghwa lightly massaged the inside of Hongjoong’s thighs, taking his time to enjoy the sight of Hongjoong all spread out for him. 

“Wow look at you, so wet for your alpha hm?” he teased as he let one of his fingers brush against Hongjoong’s entrance, collecting some slick. Hongjoong whimpered. Seonghwa reached down to lick at his leaking hole, taking his time to collect every drop of slick Hongjoong was producing. He took his time eating him out, savouring the taste and enjoying the way Hongjoong’s hole quivered every time he licked a strip up his hole. His hand explored Hongjoong’s body, enjoying the way his muscles tensed and untensed. He explored the map laid out for him, his hand accidentally brushing over Hongjoong’s nipple, which caused a high pitched moan to escape from Hongjoong. Seeing his reaction, Seonghwa started playing more with his nipples, pinching it on and off. A bit more groping and Hongjoong was starting to become impatient, grinding on Seonghwa’s tongue. 

“Ngh- Alpha~ Want you~” Seonghwa didn’t have to be told twice, he was willing to give his baby everything he wanted during this period. He flipped Hongjoong onto his stomach, ready to prep him. But seeing how wet he was and considering the fact that Hongjoong had already fingered himself, he figured prepping Hongjoong wasn’t necessary. His baby wouldn’t have minded anyways. He lined himself up to Hongjoong’s hole, inserting himself slowly. The slow insertion causing moans to escape from the both of them; Hongjoong moaning at the feeling of finally being filled up and Seonghwa moaning at the sensation of Hongjoong’s wet and tight hole. 

“Hwa~” Hongjoong whined, grabbing at Seonghwa for him to move. 

“Shh shh, it’s okay baby, I got you” he said before putting his hands on each side of Hongjoong’s face, roughly thrusting into Hongjoong, eliciting another high pitched moan. Seonghwa reached one of his hands down to pinch at one of Hongjoong’s nipples, Hongjoong arching his back at the oversensitivity. He thrusted a few more times before readjusting himself, letting most of his weight on one hand and bringing down his face to suck at Hongjoong’s other unattended nipple, the other hand still playing with his nipple. He knew how sensitive Hongjoong was, especially in his heat. A few more thrusts and Hongjoong came in between his and Seonghwa’s stomach, dick untouched. The feeling of Hongjoong tightening around him caused Seonghwa to come along with him, both gasping for air. 

They stayed like this for a few moments before Seonghwa slowly started to pull out, getting ready to clean up the mess. Before he could even pull out fully, Hongjoong flipped them over, “wanna ride you~”. Seonghwa prayed for his poor dick. He rode Seonghwa like his life depended on it, hands around his neck, whimpering. Seonghwa continued licking and nibbling on his mating mark, causing more moans and whines to spill out from him. It didn’t take long before Hongjoong came again and he eventually slowed down, breathing hard into Seonghwa’s neck. 

“Still- still hurts,” Hongjoong whimpered, Seonghwa could feel his body still shaking from the recent orgasm. 

“It still hurts?” Hongjoong nodded. 

“Do you want me to take care of it for you?” Seonghwa said before giving Hongjoong a quick peck on the lips. Hongjoong gave a soft hum in response. 

Seonghwa flipped them over, Hongjoong on his back. He lined himself up to Hongjoong’s hole and slotted himself in in one swift motion, quickly finding Hongjoong’s prostate. Seonghwa continued to abuse Hongjoong’s hole, never missing the bundle of nerves with each thrust. Without warning, Hongjoong came once again, ropes of white painting their chests. Seonghwa’s pace never changed, chasing to find his own release. The lustful pheromones Hongjoong was producing flipped a switch in him, focusing on knotting his omega. 

“Hwa!” Hongjoong was on the brink of tears, body sensitive from the overstimulation. 

“Yes baby?” Seonghwa asked, his voice husky. Hongjoong whined in response. 

“Want- want your knot. Pleasee” Hongjoong was now crying, begging to be filled up.

Seonghwa cooed, brushing Hongjoong’s hair back to get a clearer view of his face.

“Oh you want my knot?” Hongjoong managed to nod his head sharply once before he was interrupted by Seonghwa so suddenly thrusting deep into him, causing him to throw his head back, back arching to feel him deeper. 

“I’ll give you my knot” Seonghwa growled. Seonghwa didn’t lie, Hongjoong could feel his knot forming inside him and this caused Hongjoong to come again, hole clenching. A few more thrusts and Seonghwa’s knot was now fully formed and stuck inside Hongjoong. Seonghwa finally released his knot into him, filling him so full you could tell Hongjoong’s stomach was starting to get a little bloated too. Hongjoong moaned at the feeling of being filled with his alpha’s knot, body quivering and mumbling thank you’s to Seonghwa as he filled him up deeper and deeper, some of his knot spilling onto the sheets. 

“Do you feel better?” Seonghwa asked, petting Hongjoong’s head. He was tired but his baby always came first. Thankfully Hongjoong had calmed down enough for his pheromones to be lessened and Seonghwa was slowly drifting from his alpha headspace, allowing him to be more caring and gentle. Hongjoong hummed with a satisfied grin, and that was all Seonghwa needed. They slept like this, body to body, along with the dirty sheets that they were too tired to change. 

The next few days of Hongjoong’s heat went by the same. They would simply have sex, sleep, eat, repeat. Seonghwa would  _ try  _ to make them a meal in between sessions before he was interrupted by Hongjoong, who was fully naked and practically begging for dick, all whimpers and still half asleep. Seonghwa had always tried to stop him, asking Joong to give him a break. But with his adorable face and Hongjoong’s pheromones being spread around the house, how could Seonghwa say no?

Hongjoong woke up, squinting as the rays of sun hit his eyes. He wiggled around in his bed, the pain of after-sex hitting him. He could feel how puffy his rim must have been. He opened his eyes fully, slightly panicking when Seonghwa wasn’t in his line of sight. But soon relaxed when he felt arms tightening around him, the familiar smell of Seonghwa’s flowery scent hitting him. He turned around to face Seonghwa, his face twisting from feeling at ease, to disgust at the feeling of leftover mix of slick and cum dripping out of him. He sat up, staring at his leaking hole before looking towards Seonghwa, who was now half-awake, face grinning at the sight of Hongjoong.

“You made a mess” Hongjoong frowned, visibly pouting. 

“What do you mean? The rest of the house is still clean.” Seonghwa smirked, earning a smack on the shoulder. 

“No I meant inside m- you know what? Nevermind.” Hongjoong gave a look of defeat. He looked at Seonghwa, who was now making grabby hands at him, asking to be cuddled. Hongjoong allowed him, he knew the older always liked to be a small spoon despite being the alpha. They eventually settled down, finding a comfortable position for the both of them. 

“Hey Hwa.” Seonghwa hummed.

“Did you…?” Seonghwa looked up, cocking an eyebrow. It didn’t take long before he understood, smirking at the thought. 

“Every. Single. Time.” His smile got wider and wider with every word he said.

“Oh god” Hongjoong groaned, face planting himself into his pillow. 

“You were practically begging for it.” Seonghwa smiled, head going back into Hongjoong’s chest. 

“Yah!” Hongjoong hit him again, causing the other to giggle before they settled down again, groaning at the amount of washing they’ll have to do. 


	2. Seonghwa omega x Hongjoong alpha

**Summary for the Chapter:**

> He turned around to face Seonghwa, his face twisting from feeling at ease, to disgust at the feeling of leftover mix of slick and cum dripping out of him. He sat up, staring at his leaking hole before looking towards Seonghwa, who was now half-awake, face grinning at the sight of Hongjoong.  
> “You made a mess” Hongjoong frowned, visibly pouting.   
> “What do you mean? The rest of the house is still clean.” Seonghwa smirked, earning a smack on the shoulder.

**Notes for the Chapter:**

> This is a separate side story of another alternative where Hongjoong is the alpha. I know Hongjoong seemed like an omega in the main fic, but he’s just a panic gay. Here’s more fluff and a little more smut. Have fun ;)
> 
> Also I rushed editing this pls ignore my 1000001 mistakes :D

***a year ago***

Seonghwa was a late bloomer, experiencing his first heat by himself and not understanding what was happening until he visited the doctor. When he told Jaewon the reason for his absence, Jaewon was shocked. Seonghwa was tall and cold, showing all signs leading to an alpha. Jaewon never would have expected for Seonghwa to be an omega. An alpha or beta to say the least, but an omega? Jaewon took much time to process the information Seonghwa had just given him. When he had recruited him, he assumed he was a beta, not experiencing any ruts. It’s not like being an alpha was a bad thing either, there were plenty of other alpha and omega agents who used suppressants while they were at work, having some day offs for their cycle to keep them healthy. 

“Oh.” Jaewon stayed frozen, blinking. Seonghwa could tell he was shocked. He stayed silent, waiting for Jaewon to continue. 

“Are you sure?” Jaewon coughed, reaching for the cup of water on his table. 

“Jaewon, I just experienced my first heat and had a talk with a doctor, do you really think I’m not sure?” He rolled his eyes.

“Oh right, sorry. I just- I guess I just got a shock.” Seonghwa sighed. 

Seonghwa spoke up. “It’s okay. Just-” Jaewon responded by nodding his head, implying a “what’s up”.

“Could you not tell anyone? Just tell them I got sick?” Seonghwa was now fidgeting with his fingers. 

“Yes of course.” Jaewon assured him, bidding him goodbye as Seonghwa nodded and left his office. Omega assassins were looked down upon, stereotyped that they couldn’t do their jobs properly. But Seonghwa was different though, he wouldn’t let anything stop him. He knew if word about this got out and the superiors heard it, he would be dead toast. But as mentioned before, Seonghwa was different. He knew he would be able to convince his superiors to let Seonghwa stay, knowing his abilities. 

“Hey Seonghwa!” Seonghwa saw as Hongjoong waved at him, leaving some files in Yeosang’s hands before walking towards him. “Where have you been?”

“Oh… I was just sick.” He faked a cough.

“Oh are you feeling better now? Remember not to push yourself.  _ Okay love _ ?” The last words came out as a whisper, not wanting anyone else to hear it. Seonghwa nodded before he headed to his desk, remembering to take his suppressants. He didn’t want his scent to be spread around the office, people would immediately know he was an omega. And right now he didn’t want to expose his second gender to his coworkers. 

The two were at Hongjoong’s apartment, watching “How to train your dragon”. Hongjoong loved replaying the movie that reminded him of  _ his  _ black dragon, teasing Seonghwa that his black dragon was better than the one in the movie. You would think that the  **actual** Black Dragon would enjoy the movie more, but Seonghwa was starting to get tired of it. This was the seventh time that they’ve watched this movie this week. Hongjoong had one hand laying on the armrest, the other playing with Seonghwa’s hair. 

“Hey Joong, I want to tell you something.” Hongjoong hummed in response, petting his boyfriend’s head who was currently laying on his lap. 

“I’m- I’m an omega.” He blurted out, burying his head into Hongjoong’s thigh. He was clearly embarrassed and trying to hide the blush that was creeping up his cheeks. 

“I know Hwa.” Seonghwa sat up. “Huh? How-”

“You’re literally always in my lap love, it would have been ignorant of me to not notice.”

“Can’t alphas be clingy? And I’m always so cold at work anyways.” Seonghwa moved to sit against the sofa, leaning onto Hongjoong’s shoulder. Hongjoong shifted along with him, putting his arm over Seonghwa’s shoulders, making them more comfortable. 

“Hm well, I suppose yes. But I just thought of you as an omega or beta all the time. You seem like you’re only cold at work, trying to intimidate people so they wouldn’t talk to you. But in fact,” Hongjoong turned to face Seonghwa. “You’re just my little baby aren’t you?” Hongjoong cooed, pinching Seonghwa’s cheeks. 

Seonghwa tried hard at prying his hands from his face, giggling and screaming, “Yah! I gave you that petname, only  _ I  _ can use it on you. Don’t turn this around on me.” He crossed his arms and Hongjoong paused, removing his hands from Seonghwa’s face. 

“Why not, it’s cute and you seem to like it don’t you? My baby~” Hongjoong cooed and Seonghwa rolled his eyes in annoyance at the sight of Hongjoong pouting. 

“Hehe you like it~” Hongjoong said as he finally sat back, smug. Seonghwa’s silence was all that was needed for him to understand. They sat in silence, focusing on finishing the movie in front of them before heading to Hongjoong’s bed for the night, cuddling in the sheets. In the morning, the both of them headed to the agency at different timings to avoid suspicion. 

***after leaving the agency***

A few days after their party celebration, the two were on the shared sofa once again. This time, watching “Despicable me” and it was Seonghwa’s turn to tease Hongjoong, saying he looked like the minions in the movie. “Short and cute” he mentioned which earned him a hard slap on his head. The two continued their movie night, also known as their “cuddling session”. Hongjoong had his hands wrapped around Seonghwa’s neck, chin resting on his head, breathing in the faint lavender scent of Seonghwa’s shampoo. Seonghwa had his hands around Hongjoong’s waist, enjoying the way Hongjoong’s chest calmly rose and fell at a steady pace. 

“Hey Hwa- You know…” Hongjoong looked down, checking to see if Seonghwa was asleep. “I’ve been thinking.” he continued, knowing the older man was listening to him. Seonghwa was always attentive when it came to Hongjoong. 

“Do you want to spend your next heat with me? Only when you’re comfortable with it of course.” Seonghwa turned his head upwards to face Hongjoong, eyes lighting up. 

“Really? You would do that?” Seonghwa’s eyes softened, he was so unbelievably lucky. 

“Only if you want it.” Hongjoong said before leaning down to give him a peck on his forehead. 

“Yes of course I want it. There’s no one else I would spend it with.” Seonghwa said, giving him a toothy smile. “Speaking of which, my next heat is supposed to come next week~” he said shyly.

“Oh that’s great! I love you.” Hongjoong said, still looking down at Seonghwa.

“I love you too.” Seonghwa said before capturing Hongjoong’s lips, tongues dancing against each other. 

“Wait,” Hongjoong stopped, separating themselves so he could speak. Seonghwa cocked his head in confusion. 

“Then what about your previous heats? I know you took suppressants but in the last year you had to have at least  _ one  _ heat, who did you spend it with?”

“M-Myself…” 

“Really?”

“And some toys…” Seonghwa was slowly sinking into his oversized hoodie, shy from talking about this with his boyfriend. It’s his boyfriend but yet these topics get him so shy, Hongjoong thought his boyfriend was adorable. 

“Oh my god you’re adorable.” Hongjoong giggled, going forward to take Seonghwa in his arms again. Seonghwa basked in his embrace, separating them again when he felt tears on the crook of his neck.

“Joongie, what’s wrong?” He asked, petting Hongjoong trying to get him to calm down.

“You- You spent your last heat alone.” He hiccuped, letting his tears roll down his cheeks freely. Seonghwa brought his hand to Hongjoong’s cheeks, wiping his tears away using his sweater. “I’m such a bad boyfriend I should have been there with you. I'm sorry.” He sniffed. 

“Baby, I promise you. You aren’t a bad boyfriend. You’re the best boyfriend okay? You’re caring, beautiful, you’re everything I could  _ ever  _ ask for. I don’t need you during my heat, you’re right here beside me.” He caressed his cheeks, staring at Hongjoong ever so lovingly. 

“That’s a lie.” 

“What is?”

“You not needing me during your heat. Omegas  _ need  _ their alphas during their heat. If not it’s just really painful for them.” Hongjoong stared into his eyes intensely, almost glaring. 

Seonghwa was the first to break their eye contact, “yeah you’re right.” He looked down, tracing circles into the sofa. “I kept calling your name.”

“Ughhh” Hongjoong buried his head into his hands, Seonghwa looked up. “I’m really sorry.” He said, his voice muffled as he still had his head in his hands. Seonghwa caressed his back, assuring him. 

“It’s okay. I didn’t want to disturb you from work anyways.” Hongjoong looked up.

“No you wouldn’t have. I could have gotten a day off from Jaewon I’m sure he would have understood.” He grabbed Seonghwa’s hand, rubbing his hand in an effort to comfort him. 

“What and tell him that you’re helping me with my heat? Isn’t that a little suspicious? He would have known about our relationship Joong.”

“Ohhh… right…” Hongjoong’s eyes slowly widened, remembering they had to keep their relationship a secret when they were assassins. “I still feel bad though.”

“Well if it makes you feel better,” Seonghwa separated their intertwined fingers to put his arm around Hongjoong’s shoulder. “You’re helping me with my next heat, so you can make up for the previous one.” Hongjoong smiled. 

“I would love to.” They leaned closer, putting their foreheads together and rubbing their noses together, as if they were kittens. 

Seonghwa’s preheat went smoothly, other than doing some damage to their shared bank account. Hongjoong had to go to the grocery store everyday without fail to satisfy Seonghwa’s need for sweets. If Seonghwa didn’t have a particular sweet in the assigned snack cabinet, he would simply cry and whine. And Hongjoong didn’t like seeing his baby crying out of sadness. 

The day of Seonghwa’s heat came, Hongjoong was at the table busily working away on his laptop when he felt Seonghwa nudge his head between his thighs. He honestly never noticed when Seonghwa moved from the bed, only noticing him when he felt hands brushing against his leg and the scent of flowers overpowering his nostrils. He leaned back into his seat, letting Seonghwa unzip his pants and gently lick at his half hard cock. A few more kitten licks and Hongjoong was now fully hard, leaking pre-cum. Seonghwa started lapping at it, switching between licking and kissing his dick, slowly palming him. Hongjoong sat as still as he could, watching Seonghwa. Seonghwa never liked rushing, Hongjoong knew this. If Hongjoong got impatient, Seonghwa would probably get mad and cry about Hongjoong not letting him do what he wanted. 

When Seonghwa felt like he had enough of stuffing his mouth full, Hongjoong heaved a sigh of relief. He felt like he would have come if Seonghwa continued sucking at his dick. Before he knew it, Seonghwa was already straddling him, sliding the tip of his dick in. He must have fingered himself beforehand, Hongjoong thought. He watched as Seonghwa bottomed out, his ass welcoming Hongjoong. Seonghwa purred, lightly nibbling at Hongjoong’s mating mark. Seonghwa was always so good at giving love no matter the time or day it was. Hongjoong gave a few kitten licks and nibbles at his neck, never moving his crotch. With Seonghwa, things were different. 

Through Seonghwa’s first pre-heat (and heat) with Hongjoong, Hongjoong realised that Seonghwa wasn’t like other omegas in heat. Most omegas were needy and made their partner do all the hard work. Hongjoong knew this because of all the stories he had heard from his alpha friends, listening to them complaining about how sore and tired they were from helping their partner in heat. Not that he had ever spent time with an omega during their heat, Seonghwa was his first. Hongjoong felt lucky to have Seonghwa as his mate. Seonghwa wasn’t as horny as compared to other omegas during their heat. His heat mainly consisted of crying, eating, and riding Hongjoong. And unlike other omegas, Seonghwa preferred doing all the work, thus making riding Hongjoong his favourite thing to do. And Hongjoong let him. 

“Alpha please~” Seonghwa was once again riding Hongjoong, begging to be knotted. They had talked about this prior to Seonghwa’s heat, both of them agreeing that they were ready to have pups of their own and that neither of them had to take contraceptive pills. Seonghwa was eager to have Hongjoong’s knot. And pups. And Hongjoong gave it to him, knotting him everytime, leaving a satisfied Seonghwa. 

Once Seonghwa’s heat had ended and he was finally conscious enough to have a full conversation with Hongjoong, that’s when the teasing began. Again. 

“Good morning sweetheart” Hongjoong heard Seonghwa’s sweet voice beside him.

“Hey I made you breakfast, try this.” Hongjoong opened his mouth to let Seonghwa feed him, too tired to open his eyes. 

When the taste of the “food” hit him, he opened his eyes sharply, eyebrows furrowed. He quickly realised Seonghwa was naked in the sheets, laying on his stomach with his chin in his hands, with  _ no  _ sight of food beside him. Seonghwa had fed him his own cum. 

“Hwa!” He sat up, face visibly cringing. Seonghwa was outwardly laughing now, he was sure the neighbours could hear him. He continued staring at Seonghwa, clearly in disbelief. 

“What? At least you know how your cum tastes now. It’s good right?” Seonghwa reached from behind him, collecting more of Hongjoong’s knot that was leaking from his hole and bringing it to his lips, licking it seductively in front of Hongjoong. To be honest, he was still disgusted at tasting his own cum and not believing that his precious Seonghwa would ever do that to him, but Seonghwa licking  _ his  _ cum kind of turned him on. Kind of. 

“I give you my knot and this is how you repay me? Knots don’t taste good to alphas dummy, only omegas find it good. Now that I’ve tasted it, I really don’t know how you’re able to swallow my cum everytime.” He said, shaking his head. 

“Well you said it yourself, only omegas find cum yummy.” Hongjoong sighed.

“Whatever.” He said as he pulled open the sheets, letting him go to the bathroom. 

“Do you want me to follow along? I could help you take care of that problem for you.” He cocked his head, eyes motioning to Hongjoong’s erect cock.

Hongjoong looked down at it. 

“Yeah sure whatever. You still have the energy for it?” He smirked, looking up to see Seonghwa skipping happily towards him. 

Seonghwa grabbed Hongjoong’s hand. “Of course, I’ll have breakfast while I’m at it. Thank you for feeding me.” He said before smiling at Hongjoong innocently, pulling him into the bathroom. Hongjoong rolled his eyes in response, letting Seonghwa lead him. 

**Notes for the Chapter:**

> I hope you enjoyed this! Kudos and comments are always greatly appreciated. Please check out the other parts of this series!  
> -  
> -  
> -  
> I won't be writing for awhile because school is starting soon so see ya till next time!

**Author's Note:**

> I had fun writing this ngl. I hope you enjoyed this! Kudos and comments are always greatly appreciated. Please check out the other parts of this fic!  
> -  
> -  
> -  
> I just needed to switch their second genders. The urge was real. Having diff stories are funnnn


End file.
